Valve gear for the distribution valves of steam locomotives



Aprll 5, 1949. R. w. CLIFFORD VALVE GEAR FOR THE DISTRIBUTION VALVES OF STEAM LOCOMOTIVES 7 Sheets-Sheet 1 Filed 001:. 17 1945 INVENTOR e/ W C AT RNEY Apr! 5, 1949. R. w. CLIFFORD VALVE GEAR FOR THE DISTRIBUTION VALVES OF STEAM LOCOMOTIVES '7 Shets-Sheet 2 Filed Oct. 17, 1945 April 5, 1949.

VALVES 0F STEAM LOCOMOTIVES '7 Sheets-Sheet 3 Filed Oct. 17, 1945 l I & \N m.\ Qw min *1 v Q v k 6 R .3 en n on mm m E 5. m6 6 3 mm g 8 3 cm @Q .1 II I 1 2 an Q m mmw\ /.Vh, mm T R. QM. mm w w Q m m6 am w. NW. Om K A QM. Rm W R mm mm |m on. Q Q S 9. mm D m v v TI]! I v 6E I INVENTOR 750 er W C/fiord BY j 6 AT NEY Filed Oct. 17, 1945 April 5, 1949. R. w. CLIFFORD 2,466,303

VALVE GEAR FOR THE DISTRIBUTION VALVES OF STEAM LOCOMOTIVES -'7 Sheets-Sheet 4 Bye/i WCY/ m d m C WK A1: RNEY April 1949- R. w. CLIFFORD 2,466,303

. VALVE GEAR FOR THE DISTRIBUTION VALVES OF STEAMLOCOMOTIVES Filed Oct. 17, 1945 7 Sheets-Sheet 5 INVENTOR I WCI' d v NEY R. W. CLIFFORD VALVE GEAR FOR THE DISTRIBUTION April 5, 1949.

I VALVES 0F STEAM LOCOMOTIVES 7 Sheets-Sheet 6 Filed Oct. 17, 1945 R. W. CLIFFORD VALVE GEAR FOR THE DISTRIBUTION VALVES OF STEAM LOCOMOTIVES v'sheets-sheet 7 Filed Oct. 17, 1945 INVENTOR 0 e17 W. C/lfi o TORNEY C AT Patented Apr. 5, 1949 a ssgaoa VALVE GEAR FOR" THE-DISTRIBUTION VALVES OF STEAM LOCOMOTIVES Roger W. Clifford, Schenectady, N. Y, assignor; to; American Locomotive Company, New York,v N. Y., a. corporation of N'ewXork.

Application October-=17, 1945; Serial NJo; 622,76?-

7 Claims. (Cl. 12.1-12.7).

This invention relates to a. valve gear for the... distribution valves of. steam locomotives, and; more particularly to a valve gear for the'valvesi of power cylinders wherein. each cylinder at-,each end thereof has a. valve for controlling steam. admission and another. valve for controlling steamrexhaust. The valve gear-is-iurther of. the. type wherein two simultaneously rotatable cam shafts are employed; in operatingthe valves and; for controlling the valve events for steam distri butiom In valve gearv of they aforesaid; type one of; the; cam shafts; is-rotatively adjnstableoto vary the point, uncut-off .oilsteam;. n i her thercam sh -it. is rotativelyadjustable. to. a ythe. p int o a l. mission, and; exhaust of, steam.

An b of; the n entio zist providaou e; admission-exhaust: am shaft; n d is on amfor ach. p wer y inder da b e; t r ugh suite able rotat v ad us m nt i ts. ha t; or: s r ng. both for locomotive forward and reverse-or. back... ar m vem nt-l Another I object is to, provide; on; the: admission,- exhau t; am: shaft an. exhaust cam foreach... newer cylinder adagtable, throughlsuitable, rota; v a iustm nt: 0i ts s aft for-serving othi r. o omoti f rward; and reverse-- or. backward.. mov me s.

An th o ect s t rrovid onthelaum ssionexhaust, cam, shaft-1 an admission cam; and an ex; aust. m or ea h pow rv cyl nder adap abl thr u ha ine suitable rotati a iustmentot. their shaft for servingboth, for locomQtiVe, for,- ward and reversev or backwardgmovements,

Another object is toprovideon the-.tw shafts 35 a setoi; three cams, for eachpower. .cylinder each. set. comprisingva. camonthe cut-01f, cam shaft d au dm ss on. m nd. an, xhaust am n. he admission-exhaust. camshaft. The camsurfaces. of the. three cams are of. relativelengths o. adapt the hr suitab r t ti adjust-- ment ofgtheirv respective shafts; for controlling the valve events for steam distribution, Thecut ofi; cam serves-to effectall the pointsof icut-Qffmf" steam exc pt that. of. u li gear or maximum. 111 7 01f v and. they admission cam serves to, efiect" all the. points of admission ofv steamand" in addition to efiect the point of. fullgear ormaximum cut-oiIi' oi'steam.

It," should be stated-that as to the just preced= ing object, for-convenienceof description, one of' 2. thoughit also controlsaiull. gear ormaximumcut offv of. steam. These :terms; for convenience, Willi be; used hereafter in describing the preferredems bodimen-t of the invention, subject to; theabove.-"

understanding.

lo to selected pointsoivcut-ofiof'steam.. The worm;

shaft has thereon two worms,v onebeing. driven; by thev driving wheel; through aworm wheelflro tatedthereby, and; the. other rotating, the cut-oil"? cam. shaft through a worm, Wheel secured therean ons The wormsv are reversely pitched and. the.

worm. shaft, is, .in extensible, whereby rotation of" the cut-off'cam shaft for its adjustment is ef iectedby itsdrivingworm both. through itsrotation and. also, through its axial. movement.

;..This advantageously; provides maximum adjust-r merit rotation of "the cut=offcam shaft for-mini" mum axial movement of the Worm-shaft;

Another object is to provide a worm shaft rotat able by' a. locomotive driving-wheel for rotating .-.the admission-exhaust cam shaft for serving in;

the opening and closingoperationof the dis;- tribution valves. The'worm shaftis movablefbyl fluid. power axially with'simultaneous rotative:-; movement" for. rotating the, admission-exhaust? cam shaft "relativeto the driving wheel and to the? cut-offcam shaft to; simultaneously adjust its? admission cam and exhausti'camfor each cylinder to selected points ofiadmission andicorrespondingf points ofexhaust of steam andfor reversing tli'ev.

movement of the locomotive. Ordinarilyychan'ge \has"thereon two worms, one being driven bythe'? driving wheel through a worm wheel. rotatedf; thereby, and, the other rotatingthe admission exhaust cam" shaft through a worm wheel se curedthereon; The worms are -reverselypitched? andtheworm shaft isinextensible; wherebyro tation of the admission exhaust camshaft" fort itsadjustment i'sefiected b'y its driving worms both through its rotation; and; also" through its; axial-"- movementt This-advantageously providese:

5a? maximum: adj ustmentirotationuof ith-ez admissions 3 exhaust cam shaft for minimum axial movement of the worm shaft.

Another object is to provide steam admission and steam exhaust valves for the power cylinders housed each in a casing provided at its outer end with a small steam cylinder. Each valve has a stem at one end serving as a plunger operating in the small steam cylinder. In the case of the admission valves, each valve has a rocker lever rocked outwardly by the joint action of its correlated cut-off and admission cams. In the case of the exhaust valves, each valve has a rocker lever rocked outwardly by its correlated exhaust cam. Each valve has a stem at its other end engaging its rocker for movement of the valve in one direction by the outward movement of its rocker. The valve is returned'iby the pressure of the steam in the small steam cylinder as the cams (or cam as the case may be) in their rotation permit the rocker to rock inwardly. Thus the valve stem engaging the rocker is held in constant contact therewith and the rocker (through rollers) is held in constant contact with its cams (or cam as the case may be), all in a most simple manner and without the employment of any spring.

Another object is to provide piston valves for the power cylinders. Each valve reciprocates in a valve cylinder housed in a valve chest or casing and operating as a double valve in the sense that the steam is passed at both ends of the piston valve when. open- To this end the valve casing in elfect is divided into twosteam passages, one at each end of the piston valve. In the case of an admission valve the live steam coming from the "supply port opening of the casing passes through both admission casing passages to the power cylinder port. In the case of an exhaust valve the exhaust steam coming from the power cylinder port passes through both exhaust casing passages to the exhaust port or opening in the casing.

Other and further objects ofthis invention will appear from the following description, the accompanying drawings and the appended claims.

Referring to the drawings forming part of this application, Figure 1 is a diagrammatic fragmental side elevation of the right side of a steam locomotiveembodying the present invention, parts being shown in dot and dash lines; Fig. 2 is a view similar to Fig. l of the left side of the loconiotive; mg. 3 is an enlarged section on the line III-III of Fig. 1; Fig. 4 is an enlarged section on the line IVIV ofFig. 3; Fig. 5 is an enlarged section on the line V-V of Fig. 3; Fig. 6 is an enlarged elevation of one of the rocker levers, and its associated parts, of Fig. 4; Fig. 7 is a section on the line VII-VII of Fig. 6; Fig. 8 is an enlarged elevation of one of the rocker levers, and its associated parts, of Fig. 5; Fig. 9 is a view of Fig. 8 viewed from the left; Fig. 10 is an enlarged foreshortened section on the line XX of Fig. 3, parts being omitted and the valve'cylinders being shown in axial section; Fig. 11 is an enlarged vertical longitudinal central section, partly in full, of the rear end of the cut-off cam shaft drive; Fig. 12 is a view, similar to Fig. 11, partly in section and partly in full, of the front end of the cut-off cam shaft drive; Fig. 13 is an enlarged vertical longitudinal central section, partly in full, of the rear end of the admission-exhaust cam shaft drive; Fig. 14 is a view, similar to Fig. 13, partly in section and partly in full, of the front end. of the admission-exhaust cam shaft drive;

4 and Fig. 15 is a diagram of various positions of the cams for various distribution valve events.

Features of the invention are adaptable to engines other than to locomotive engines, and poppet valves may be employed as well as piston valves. But as the invention is especially adapted to steam locomotives and as piston valves are preferable, the invention is so illustrated in the drawings and will be so confined in the description, the scope of the appended claims being however not so limited unless so indicated.

Only sufficient of the locomotive is shown for an understanding of the invention. It is indicated generally by the reference numeral l and includes main side frames 2, a cylinder saddle 3, a superstructure 4 with a smoke box 5 at its front end and a cab 6 at its rear end, axles 1, 8 and e, and pairs of driving wheels l9, II and 12 on the respective axles, which are connected by the usual side rods (not shown). The locomotive further includes a crank pin I 3 for each of the main driving wheels'li, an arm 14, for a purpose later to be described, extending in- N wardly from each crank pin 13 to the axle 8, and

two brackets l5 and I6, bracket [5 being at the locomotive right side, and bracket 16 being at the locomotive left side, the brackets being disposed above the main driving axle 8. The crank pins I3 are angul'arly disposed according to usual practice.

The saddle 3 and parts associated therewith include a right power cylinder IT, a left power cylinder 18 and the usual common exhaust opening l9 leading to the smoke stack (not shown).

Each cylinder has a cylinder liner 2!], a piston 2!, a piston rod 22, a crosshead 23, a main rod :4 connecting the crosshead with the adjacent crank pin I 3, and two valve chests 25. The chests are alike except that they are oppositely directed, one chest being at the front end of the cylinder and the other chest being at the rear end.

Each chest includes an outer end wall 26, an inner end wall 21, two side walls 28 and 29, a top Wall 30, a bottom wall 3 I, two valve cylinder-supporting interior walls 32 and 33 spaced from each other and from the walls 28 and 29 respectively and extending from top to bottom and from end to end of the chest, and two walls 34 and 35 connecting respectively walls 28 and 32, and walls 29 and 33. Each chest is thus divided interiorly into an enclosed space or passage 36, which, as will later appear, is common to both the admission and exhaust valves, two outer spaces or passages 31 and 38 forming a compartment 39 for live steam, and two inner spaces or passages 40 and 4t forming a compartment 42 for exhaust steam.

The passage 315 communicates at its bottom, through a large opening 43 in the bottom wall 3|, with a live-steam-exhaust passage 44 formed in the saddle 3. The passage 44 communicates, through a large opening 45 in the power cylinder, with a live-steam-exhaust port 46 formed in the cylinder liner 20.

The live steam compartments 39 at opposite ends of a power cylinder have each at its top a large pipe coupling 47 which is connected with one of the branches of a live steam supply pipe 48. The exhaust steam compartments 42 at each end of a cylinder are open, at their inner end walls 21, each to a steam exhaust pipe 49 which discharges the exhaust steam through the opening 19 in the usual manner.

A piston valve cylinder 58 is supported in aligned orifices in the walls 32 and 33 in each compartment with its axis parallel with the axis of the power cylinder liner 20. A bored piston valve stem guide -5l extends through an orifice in the wall 29 in each of the compartments with its axis in line with its correlated piston valve cylinder axis. A head or cover 52 closes an orifree in the wall 28 in each of the compartments. Each cover has a small steam cylinder 53 formed therein with its axis in line with its correlated piston valve cylinder axis. Each cylinder 53 has a threaded orifice 54 for a steam supply pipe (not shown) for supply of steam to the cylinder 53 from any convenient source. The piston valve cylinder is open at both ends, spans the passage 36 and extends and opens into the compartment assages adjacent thereto.

The valve cylinder is grilled at its end adjacent the cover 52 for improved steam flow. The valve cylinder is smaller circumferentially than the spaces or passages adjacent thereto thereby providing ample space for the flow of steam. The valve cylinder is open to the passage 36 through a circumferential row of ports 55, and at each side thereof the valve cylinder has a solid portion 56 tightly engaging the walls 32 and 33.

From the foregoing it will be seen that as to each valve chest live steam will flow from the pipe coupling '41 to the power cylinder through both ends of the steam admission valve cylinder, and exhaust steam will flow from the power cylinder to the exhaust pipe 49 through both ends of the steam exhaust Valve cylinder. Further it will be seen that there is a steam admission and a steam exhaust valve cylinder at each end of each power cylinder. The valve cylinders at one end are each in axial alignment with the corresponding valve cylinder at the other end and all four valve cylinders have their axes parallel with the axis of the power cylinder.

There is a piston valve and its associated parts for each piston valve cylinder. These are similar except that they are in reverse positions at opposite ends of the power cylinder and further except that the steam admission valves have axial openings connecting their ends while the steam exhaust valves have not. However either type of valve may be employed as desired. Each valve has, atits opposite ends, radially extended portions provided with rings which engage the inner face of its piston valve cylinder. The valve gear is so designed that to move a valve from'closed to open position it is moved toward the adjacent cover 52, conveniently termed outward movement.

Each steam admission valve 51 has the aforesaid radially extended portions 58 and is provided at its end adjacent the cover 52 with a stem or plunger 59 and at its other end with a stem 60. The stem 60 extends through the adjacent guide 5| with its end in engagement with a rocker lever (later to be described). The plunger 59 extends into the adjacent cylinder 53.

During the operation of the valve gear the rocker lever is forced to rock outwardly thereby moving the valve 51 outwardly to open position. When the rocker lever is free to rock inwardly the plunger 59, due to the pressure of the steam in cylinder 53, returns the valve to closed position, the stem 60 always remaining in contact with its rockerlever. When the admission valve 51 is closed its extended portions 58 will engage the valve cylinder solid'portions 56 thereby shutting on the ports 55 and oons'equently'the corre= spending end of the power cylinder from live steam supply. when the admission valve 51 is open its outer extended portion 58 will be suitably over the grilled end of the valve cylinder and the inner extended portion 58 will be suitably over the ports to permit live steam to enter ports 55 and consequently the corresponding end of the power cylinder through both ends of the valve cylinder from both passages 31 and 38.

Each steam exhaust valve 6| has the aforesaid radially extended portions 62 and is provided at its end adjacent the cover 52 with a stem or plunger 63 and at its other end with a stem 65. The valve 6|, portions 62, plunger 63 and stem 64 are disposed and operated respectively in a manner similar to admission valve 51, portions 58, plunger 59 and stem and no further description is deemed necessary.

A cam box 65 is disposed between the valve chests 25 of each power cylinder. Each box has side walls 66, end Walls 61, a bottom wall 68 and a top wall 69. The side walls 66 have flanges 10 and the walls 29 have flanges H. The flanges 16 rest upon and are bolted to the flanges ll, thus rigidly holding the box in place. The top wall 69 is open and a cover plate 12 is bolted thereto. The outer end wall 61 is detachably bolted to flanges on the side walls '66. The inner end wall 61 has two stuffing boxes 13 vertically aligned one above the other. The outer end wall 61 of the box for the left power cylinder has an opening 14 in line with the lower stuffing boxes 13. The opening 14 is-enclosed by a gear casing 15 formed on the adjacent outer end 'wall 61. The outer end wall 61 of the box for the right power cylinder has an opening similar to the opening 14 in line with the upper stuffing boxes 13 and the opening is enclosed by a gear casing 16 formed on the adjacent outer end wall 61.

A rotatable steam admission-exhaust cam shaft 17 extends transversely across the locomotive, through the lower stuffing boxes 13 and in to the cam boxes 65. It extends into the gear casing 15 and has secured on its end within the gear casing a worm wheel 18 for rotating the shaft.

A rotatable steam cut-off cam shaft l9 extends transversely across the locomotive, through the upper stuffing boxes 13 and into the cam boxes 65. It extends into the gear casing 16 and has se cured on its end within the gear casing a worm wheel for rotating the shaft.

The cam shafts ll and 19 are journalled in bearing blocks 8| disposed in the cam boxes 65 and secured to the bottom walls 68 thereof. The

shafts are journalled for rotation only, that is to say, they have no axial movement.

The lower shaft has secured thereon, in each of the cam boxes 65, a steam admission cam 82 having a raised cam face 8-3, a low face 84, and side faces 85 connecting the raised and low faces. The stems 60 of the steam admission valves 51 of a power cylinder extend toward each other in alignment through the side walls of their adjacent cam box 65 and the admission cam 82 therein is in the vertical plane of these stems.

The lower shaft 11 also has secured thereon, in each of the cam boxes 65, a steam exhaust cam 86 having a raised cam face 81, a low face 88 and side faces 89 connecting the raised and low faces. The stems of the steam exhaust valves 6| ofa power cylinder extend toward each other in alignment through'the sides of their adjacent cam box 65 and the exhaust-cam 86 therein is in the verticalplane of these stems.

The upper shaft I9 has secured thereon, in,

each of the cam boxes 65, a steam cut-off cam 90 having a raised cam face 9I, a low face 92 and side faces 93 connecting the raised and low faces. The admission cam 82 and the cut-off cam 90 in each cam box 65 are in the same vertical plane.

The cam rocker mechanism is similar in each cam box 65. Therefore but one mechanism will be described. A rockerlever 941s disposed at each side of the pair of cam shafts I1 and I9 opposite the cams 82 and 90. Each lever is pivotally hung from a bracket 95 projecting inwardly from the adjacent side of the cam box 65. A roller support 96 is pivotally connected about midway thereof to each of the levers at a point thereon below the lever pivotal connection with its bracket, and about on a horizontal line midway between the cam shafts. The levers and supports are respectively similar except they are reversed. Each support has a cam roller 91 journalled therein at its upper and lower ends. The lower rollers engage the faces of the cam 82 and the upper rollers engage the faces of the cam 90. The lower end of each rocker lever engages the end of the valve stem 60 adjacent thereto.

A rocker lever 98 is disposed at each side of the cam shaft Ti opposite the cam 86. Each lever is pivotally hung from a bracket 89 projecting inwardly from the adjacent side of the cam box 65. Each lever has a cam roller I journalled therein below its pivotal connection and opposite the cam 86. The rollers engage the faces of the cam 85. The lower end of each rocker lever 98 engages the end of the valve stem 64 adjacent thereto.

The cam shafts are rotated in unison in the same direction and at the same speed by the locomotive main driving axle through a train of gears at the left side of the locomotive for the admission-exhaust cam shaft TI and through a train of gears at the right side of the locomotive for the cut-01f cam shaft I9, as will later be described.

The cam shafts make one revolution for each complete cycle of the power piston and accordingly one revolution of the driving wheels and their axles. The rotation of the cam shafts is clockwise as viewed in Figs. 4 and 5 for locomotive forward movement, but will be counter-clockwise for locomotive backward or reverse movement.

Referring more particularly to Fig. 4, each steam admission valve is moved outwardly (port opening direction) by its rocker lever $4 when it is rocked outwardly against a cushion of steam in cylinder 53. The outward rock of the lever is effected by its revolving cams and the engaging rollers, which latter roll upon the cam faces from the low to the raised faces, the valve being fully open when both rollers are riding upon their raised cam faces. The inward movement (portclosing direction) is effected by the steam pressure in cylinder 53 acting on plunger 59. This is effective only when the rollers are leaving the raised cam faces and are riding towards and upon the cam low faces which permits gradual inward rock of the lever. Full port-closing is effected when one of the rollers rides upon its cam low face, and full valve movement in a closing direction is effected when both rollers are riding upon their cam low faces.

From the foregoing it will be seen that the stems 68 are constantly in engagement with their levers and the rollers are constantly in engagement with their cams thereby obtaining a smooth valve movement in both directions. The admission valves at the opposite ends of a power cyl- 8. inder operate ina similar manner except with different timing, according to usual practice.-

The raised face of the admission cam 82 is of a shorter length than that of the cut-off cam 90. The roller of the cut-off cam always reaches its raised cam face first. Subsequently thereto the roller of the admission cam reaches its raised cam face thereby admitting steam to the power cylinder. Thus cam 82 is termed a, steam admission cam. When the cut-off cam is adjusted for full gear cut-off (longest cut-off) the roller of the admission cam will leave its raised cam face first thereby effecting cut-off. Thus cam 82 is always the admission cam and also the cut-off t cam for full gear cut-off. Cam 9B is the cut-off cam for all other cut-offs, and in each such instance the roller of the cut-off cam leaves its raised cam face before the roller of the admission cam leaves its raised cam face, thereby effecting the other various cut-offs.

Referring more particularly to Fig. 5, each exhaust valve operates similarly to the admission valves and no detailed description is therefore deemed necessary. For each of the power cyl-' inders there is only one exhaust cam 86. This is secured on the admission-exhaust cam shaft 71. There is accordingly only one roller for each rocker lever 98. The exhaust cam 86 (Fig. 5) is secured on its cam shaft angularly relative to its companion admission cam 82 (Fig. 4) so that the exhaust valve at each end of a power cylinder opens and closes in the reverse order to that of its adjacent admission valve and in the same order as the admission valve at the opposite end of the power cylinder. The exact timing of the opening and closing of an exhaust valve will depend upon the angular position of the exhaust cam and the length of its raised cam face.

Figs. 4 and 5 show the same position for the cam shafts, this position being for locomotive forward motion, full gear, no lead, crank of power piston on front dead center. Here the admission valve at the right (front) is just about to open and its adjacent exhaust valve is closed, while at the left the admission valve is closed and its adjacent exhaust valve is open.

It has been stated that the cam mechanisms in the two cam boxes are similar. The corresponding cams are set, however, at different angles according to the angle setting of their driving axle crank pins I3 required for proper timing of the power piston movements in accordance with usual practice.

The gear train at the left of the locomotive for rotating the admission-exhaust cam shaft I! by the locomotive main driving axle 8 and the parts associated with the train of gears include the worm Wheel I8 secured to the shaft 11 in gear casing I5 (see particularly Figs. 13 and 14), a worm IIlI below and in mesh with worm wheel I8, a rotatable shaft I02 extending rearwardly from worm IOI, a worm I 03 on the rear end of shaft I92 reversely pitched as to worm I0 I, and a worm wheel I04 below and in mesh with worm I 03. The worms NH and I93 are formed on the shaft I02 and the shaft I 02 is inextensible.

The casing I5 includes a cylinder I05 at the forward end of which is a shorter cylinder I06, the cylinders being separated by an orificed wall Illl. A reciprocable tubular plunger I68 having a forward head I09 is disposed in cylinder I05. The cylinder I05 has an orificed head III! at its rear end. The shaft I02 at its forward end extends through this orifice and the worm IIH ismounted in the plunger I08 by ball bear accuses ings III. The worm IN, and consequently the shaft I02, are held against longitudinal movement in the plunger I08 relative to the ball bearings by shoulders II2 formed on the shaft I02 and a key H3 in the forward end of the shaft. The ball bearings are held against axial movement by shoulders I I4 formed on the plunger I08. The plunger and cylinder are orificed to permit intermeshing of the Worm WI and worm wheel 18.

A reciprocable piston H5 is housed in the cylinder I06. It has a rear piston rod II6 extending through the orifice in wall I01 into the forward end of cylinder I05. It has a fluted piston rod II1 extending from its forward end. The cylinder I06 has a forward head II8 provided with a small guide H9 in which the rod II1 extends. The cylinder I05 at its forward end has a pipe coupling orifice I20 and the head II8 has a pipe coupling orifice I2I, the couplings being connected respectively with power fluid pipes I22 and I23 extending rearwardly of the locomotive (see Fig. 2).

A gear casing I24 is disposed at the rear end of shaft I02 and is bolted to bracket I6. The worm wheel I04 is housed in casing I24 on. the inner end of the adjacent arm I4 concentric with the driving axle 8 by a flexible coupling I25 of usual construction to permit the axle to tilt under service conditions in the usual manner.

A cylinder I26 forms part of the casing I24. It has a forward orificed head I21 and a rear head I28 provided with a stop lug I29. A reciprocable tubular plunger I30 having a rear head I3I is disposed in the cylinder I26. The shaft I02 at its rear end extends through the orifice in the head I21 and the worm I03 is mounted in. the plunger I30 by other ball bearings III. The worm I03, and consequently the shaft I 02 are held against longitudinal movement in the plunger I30 relative to the ball bearings by shoulders and a key, and the ball bearings are held against axial movement by shoulders in the plunger I30, all in a manner similar to that already described in connection with the worm I0! and plunger I 08. Likewise the plunger I30 and cylinder I26 are orificed to permit intermeshing of the worm I03 and worm wheel I 04.

The cylinder I26 at its rear end has a pipe coupling orifice I32, the coupling being connected with a power fluid pipe I33 extending rearwardly of the locomotive (see Fig. 2). Any suitable power fluid may be provided for pipes I22, I23 and I33, such as air, steam or a hydraulic fluid. In the instant case, by way of example, the fluid will be assumed to be compressed air.

Forward of the cab 6 is a compressed air supply tank I34 connected for supply of compressed air from any source in the locomotive by a connection (not shown). Within the cab is a valve casing I35 having an inlet port I36 to which is 'connected a compressed air pipe I31 also con.-

nected to the supply tank I34 for supply of air to the casing. The casing has an outlet port I38 to which is connected the compressed air pipe I33. another outlet port I39 to which is connected the compressed air pipe I22, an exhaust port I40 to which is connected an exhaust pipe I4I, a rotatable valve element (not shown) selectively connecting ports I38 and I39 with the supply port I36 and with the exhaust port I40 so that when compressed air is supplied to the pipe I33 it will be exhausted from with head I21.

pipe I22, and vice versa. The valve element is operated by a hand lever I42.

Within the cab and below the valve casing I35 is another valve casing I43 for a reciprocable piston valve (not shown). Casing I43 has three ports I44. The uppermost port is an inlet port and is connected with a compressed air pipe I45 which is connected with pipe I31 for supply of compressed air to the casing I43. The intermediate port is an outlet port and is connected with pipe I23, and the lowermost port is an outlet port and is connected with an exhaust pipe I 46. Extending through the bottom Wall of the valve casing I43 is a piston rod I41 extending from the aforementioned piston valve (not shown). Below the casing I43 is a hand operated device I48 which effects adjustment of the cut-off cam shaft 19, as will later be described. It also effects operation of the piston rod I41.

The valve device having the hand lever I42, the valve device having the piston rod I41, the device I48 and the flexible coupling I25 with its arm I4 are all well-known pieces of apparatus and form, in and of themselves, no part of the present invention. For a fuller understanding of their parts and their operation reference is made to the patent to the present applicant, No. 2,135,032, November 1, 1938, see particularly Fig. 27, Figs. 21 through 24, Figs. 13 through 1 and Fig. 19.

The operation of the mechanism including the train of gears and their associated parts at the left of the locomotive is as follows, referring more particularly to Figs. 13 and 14:

The driving axle 8 drives the admission-exhaust cam shaft 11 by the train of worms and worm wheels as has already been explained, the admission-exhaust cam shaft making one revolution for each revolution of the axle. This mechanism is also for reversing the locomotive from forward motion to backward motion and vice versa. This is accomplished by moving the shaft I02 longitudinally. During this movement the shaft, with its worms, will rotate due to the angularity of the teeth on worm I03. The Ion; gitudinal movement forces the worm I03 to rotate in. mesh with worm wheel I04 and relative thereto. The longitudinal movement of shaft I02 causes the worm ml to rotate its worm wheel 18 and the rotation of the shaft I02 causes the worm IM to further rotate its worm wheel 18 due to the reverse direction of the pitch of the worms IM and I03. Thus is provided the maximum rotation of the admission-exhaust cam shaft 11 for minimum longitudinal movement of shaft I02.

The position of the parts as shown in Figs. 13 and 14 is that for locomotive forward movement. To obtain this position it is assumed that compressed air was supplied through orifice ,I32 to the rear end of cylinder I26 and, simultaneously therewith, that compressed air was exhausted through orifice I20. This movement is checked, as shown, by plunger I 30 coming into contact To reverse the locomotive compressed air is supplied through orifice I20 and, simultaneously therewith, compressed air is exhausted through orifice I32. This reversal movement is checked by head I3I coming into contact with stop lug I29. Thus locomotive reversal from forward to backward movement, and vice versa, is accomplished by merely giving the admission-exhaust cam shaft 11 a partial rotation relative to the driving axle 8 to shift the 7 I56 by ball bearings I51.

' It has a forward orificed head IISI.

II 6 engaging with head I09 serves as a stop and A there will be a corresponding space between the head I21 and plunger I30. In other words the admission valve and exhaust valve will assume a different position relative to the driving axle 8, that is to say a position of lead or preadmission,

which is assumed in the present instance as being about 15% lead or preadmission. In practice the cross-sectional area of cylinder I should be somewhat greater than that of cylinder I05, and is so shown, or other means should be resorted to to provide an increased pressure in cylinder I09.

As already mentioned the adjusting movements for shaft I02 are under the control of the engineer through the devices in the cab.

It will be seen from the above that the admission-exhaust cam shaft has but a single admis- 2 sion cam and exhaust cam for each power cylincler and that all that is necessary to reverse the engine is to rotate this shaft and. accordingly its cams an appropriate amount relative to the driving wheel to effect reversal of the locomotive.

The gear train at the right of the locomotive for rotating the cut-off cam shaft 19 by the locomotive main driving axle 8 and the parts associated with the train of gears are best shown in Figs.

11 and 12 and include the worm wheel 80 secured to the shaft 19 in gear casing 16, worm I49 below and in mesh with worm wheel 80, a rotatable shaft I50 extending rearwardly from worm I49, a worm I5I on the rear end of shaft I50 reversely pitched as to worm I49, and a worm wheel I52 below and in mesh with worm I5I. The worms I49 and I5I are formed on the shaft I50'and the shaft I50 is inextensible.

The casing 16 includes a cylinder I53.

rear head I55. A reciprocable tubular sleeve I56 is disposed in cylinder I53. .The shaft I50 at its forward end extends through the orifice in the The cylinder has a forward head I54 and an orificed head I55 and the worm I49 is mounted in sleeve..-

consequently the shaft I50, are held against longitudinal movement in the sleeve I 56 relative to the ball bearings by shoulders and a key, and the ball The worm I49, and

bearings are held against axial movement by.

shoulders in the sleeve I56, all in a manner simi-" shaft I50 and is bolted to bracket I5. The worm wheel I52 is housed in the casing I58 and connected to the inner end of the adjacent arm. I4 concentric'with the driving axle 8, by a flexible coupling I59 similar to that of, and for the same purpose as, the flexible coupling I25.

A cylinder I60 forms part of the casing I58.

A reciprocable tubular sleeve IE2 is disposed in the cylinder I60. The shaft I50 at its rear end extends through the orifice in the head ISI and the worm I5I is mounted in the sleeve I62 by other ball bearings I51. The worm I5I, and consequently the shaft I50, are held against longitudinal movement in the sleeve I62 relative to the ball bearings by shoulders and a key, and the ball bearings are held against axial movement by shoulders in the sleeve I52, all in a similar manner to that already described in connection with worm I49 and sleeve I50. Likewise the sleeve I52 and cylinder I50 are orificed to permit intermeshing of the worm I51 and Worm wheel I52.

The two plungers I08 and I30 and the two sleeves I56 and I62 reciprocate but do not rotate. They are held against rotation by a key in the plunger or sleeve, as the case may be, and a keyway in the cylinder, the key I53 and the keyway I54 being shown in Fig. 11 for the sleeve I52 and cylinder I60.

The sleeve I 52 to the rear of the rear ball bearings I51 has internal threads I05 and is open at its rear end. The casing I58 has a detachable part I99, at the rear end of which is a detachable shaft support I61, at the rear end of which is a detachable cap or cover IE8. A rotatable shaft I99 is mounted at its rear end portion in ball bearings I10 in the support I61. The shaft I69 is held against axial movement relative to the ball bearings by shoulders on the shaft and by keys "I and the ball bearings are held in place by shoulders formed in the support I61. A bevelled gear 12 is secured on shaft I69 just forward of the forward ball bearing I10. A wheel I13 having external threads I14 is secured on the front end of shaft I59 and threaded in the internal threads I65 of sleeve I62.

A rotatable shaft I15 having a sleeve I16 secured thereon is mounted in ball bearings I11 in an extension I18 of the detachable part I 58. The shaft I15 is held against axial movement relative to the ball bearings I11 by shoulders formed on the sleeve I16 and shaft I15 and the ball bearings are held in place by shoulders formed in the extension I18. The shaft I15 has a shaft coupling I19 at its rear end and a bevelled gear I secured on its front end portion and in mesh with gear I12. The shaft I15 is held against axial movement'by a collar I8I formed on its rear end portion, the collar providing one of the aforesaid shoulders, and a key I82 at its forward end forwardly of gear I80.

The aforementioned device I48 located in the cab 6 has a casing I83 and a rotatable shaft I84 extending through both ends of the casing. A hand wheel I85 is secured to the rear end of shaft I84 and a shaft coupling I89 is secured to the shaft I84 at its front end. As before mentioned, for a fuller understanding of the device I48 reference may be had to the aforementioned Patent No. 2,135,032 (Figs. 21 through 24). A shaft I81 connects shaft I15 with shaft I84 by universal joints I88 of usual construction connected to the shaft couplings I19 and I06.

The operation of the mechanism, including the train of gears and their associated parts at the right of the locomotive is as follows, referring more particularly to Figs. 11 and 12: The driving axle 9 drives the cut-off cam shaft 19 by the train of worms and worm wheels as has already been explained, the cut-off cam shaft making one revolution for each revolution of the axle.

This mechanism is also for changing the points of cut-off. This is accomplished by moving the shaft I50 longitudinally. During this movement the shaft, with its worms, will rotate due to the angularity of the teeth of the worm I5I. The longitudinal movement forces the worm I5I to rotate in mesh with worm wheel I52 and relative thereto. The longitudinal movement of worms I49 and I I.

events. 'oif cam shaft I9 and the admission-exhaust cam shaft I50 causes the worm I49 torotate'its worm Wheel 80 and the rotation of the shaft causes the worm I49 to further rotate its worm wheerbo due to the reverse direction of the Pitch of the Thus is provided maximum rotation of the cut-off cam shaft I9 for minimum longitudinal movement of shaft I50. I

The position of the parts as shown in Figs. '11 and 12 is that for full gear or maximum cutoff, which is accomplishedby the admission eam 82 as aforesaid. The sleeves I62 and I56 move with their respective worms I 5| and I49 during their longitudinal movements to vary the 'cut off,

the sleeve I62 being effective in producing this movement.

By turning the hand wheel I85 in one direction or the other the wheel H3 is turned accordingly through the connecting mechanism already described in an obvious manner. The turning of the wheel I I3, through the engagement of its threads I74 with the threads I65, effects the aforesaid longitudinal movement of the sleeve "Hi2 forwardly or rearwardly as the case may be. Provision is made at the device I-48 for the operator of the hand wheel i 85to adjust the gear to the desired points of cut-off and to effect preadmission for forward motion if desired.

Fig. 15 shows the three cams for each power cylinder in engagement with their respective rollers for various valve events. The three cams are arranged in vertical rows and each rowillustrates a different valve event, there being four such There are but two cam shafts, the cutshaft 'II beneath camshaft I9. On the cam shaft I9 is the cut-off cam 90 in engagement with its rollers 91 and on the cam shaft TI is the admission cam 82 in engagement with its rollers =91. As the exhaust cam is on the cam shaft "'I'I, this cam shaft in Fig. 15 is repeated at the bottom so that the exhaust cam 86 andits rollers I80 may be clearly seen.

The cam shafts of the first three vertical rows, as indicated by the arrows, are rotated clockwise y for locomotive forward movement. The cam shafts of the fourth vertical row are'r'ota'te'd counter-clockwise for locomotive reverse or backward movement.

The upper two rollers and the lower roller at the left of the cam shafts operate respectively III] the admission valve and exhaust valve at one end of the ower cylinder, and the upper two rollers and the lower roller at the right of the cam shafts operate respectively the admission valve gages its correspcnding roller 91. Therefore cam 8 2 always serves as the admission cam.

Came in the second vertical row are in the same relative angular positions as in the first vertical row but in the normal rotation of their shafts "they have reached the position for locomotive engine crank at front cut-off. Here the cam face .91 is in engagement with its roller 91 at the right while the cam face 83 has left its roller 91 at the right thereby effecting cutoff.

The cams in the third vertical row are in different relative angular positions than those .in the first "two rows; These positions are for forward movement short cut-off, approximately 5%, and for lead .or preadmission, approximately 15%, the crank being on front dead center-similar to the first vertical row. Here the raised face ll-80f cam 82, which is not now acting as a euteff cam, is about to engage its roller 9'! at the right and the raised face 9| of cain 90, which is now acting as the cut-off cam, is about to leave its roller91 at the right to effect the 5% cut 'off. For this setting of the cams the cam 90 has been angularly shifted or adjusted for the short cutoff and the cams '82 and 86 have been angularly shifted or adjusted for the preadmissi'on or lead.

The cams in the fourth vertical row have the same angular positions relative to each other as the Game in the first row, but are for reverse *or backward movement, full gear, no lead, with the crank on front dead center. The cam 90 is in the same position as the cam 98 of the third row. The cams 82 and 86 have been angularly shifted or adjusted to effect the reverse or backward movement of the locomotive. Here again in this position the cam 82 acts as the cutoff cam for full gear or maximum cut-off.

While there has been herein described an approved embodiment of this invention, it will be understood that many and various changes and modification in form, arrangement of parts and detail of construction maybe made thereto without departing from the spirit of the invention, farm that all such changes and modifications as fall within the scope of the appended claims are contemplated as a part of this invention.

The invention claimed and desired to be secured by Letters Patent is:

1. A steam engine comprising two distribution valve-controlling rotary cam shafts; a cut-off cam on one of said shafts; another cam on the other of said shafts; and me'ansfor rotating said cut-off cam shaft relative to said other cam shaft and exhaust valve at the other end of the power II" to ange the point of cut-off of steam;- Sa (Mtcylinder.

The cams in the first vertical row are in angular positions to position their rollers so that the admission and exhaust valves at one end of the power cylinder are respectively closed by the upper two rollers and opened by the lower .ro'lller at the left of the shafts, and so that the admission and exhaust valves at the other end of the power cylinder are, respectively, about to open by the upper two rollers and closed by the lower roller 68 at the right of the shafts.

The cams are at positions for forward movement, full gear, no lead, locomotive engine crank on front dead center. In this position of the cut-off cam 90 the admission cam 82 will also serve as the long cut-off cam as its raised face 83 will leave its roller 91 at the right before the raised face 9I of the cam 99 leaves its roller 91 at the right. The raised face 9I' always enoff cam having a cam face sufficiently longer than the cam face of said other cam, and said cams cooperating and being angularly disposed so that said other cam controls both admission and cut-off atone of its angular positions rela tive to said cut o'fi" cam and controls admission only at ether of its angular positions relative to said cut-off cam.

2. A steam engine comprising two distribution valve-controlling rotary cam shafts; a cut-off cam on one of said shafts; another cam on the other of said shafts; means for rotating said outoff cam shaft relative to said other cam shaft to change the point of cut-off of steam, said cut-01f cam having a longer cam face than said other cam and said cams cooperating and being angula-rly disposed so that said other cam controls both admission and cut-off at one of its angular positions relative to said cut-off cam and congages its roller 91 before the raised face 83 en- 7 trols admission only at other of its angular po- 3. A multi-cylinder steam engine comprising,;

two distribution valve-controlling rotary cam shafts; a set of three cams on said shafts for each cylinder, each set including a cut-ofi cam on one of said shafts, another cam on the other of said shafts and an exhaust cam on said other shaft; and means for rotating said cut-off cam --"s'haft relative to said other cam shaft to change the point of cut-off of steam, said cut-ofi cam having a cam face sufficiently longer than the cam face of said other cam, and said cut-off cam and other cam cooperating and being angularly disposed so that said other cam controls both admission and cut-01f at one of its angular positions relative to said cut-off cam and controls admission only at other of its angular positions relative to said cut-ofi cam.

4. A multi-cylinder steam engine comprising two distribution valve-controlling axially immovable rotary cam shafts; a set of three cams on said shafts for each cylinder, each set including a cut-off cam on one of said shafts, another cam on the other of said shafts and an exhaust cam on said other shaft; means for rotating said out- 4 off cam shaft relative to said other cam shaft to change the point of cut-off of steam, said cut-01f;

cam having a longer cam face than said other cam and said cut-off cam and other cam cooperating and being angularly disposed so that said other cam controls both admission and cut-off at one of its angular positions relative to said cut-off cam and controls admission only at other of its angular positions relative to said cut-off cam; and means for rotating said other cam shaft relative to said cut-01f cam shaft to change the point of admission of steam.

5. In a steam locomotive, the combination of driving wheels; a steam power cylinder having a port; a piston for said cylinder; a valve controlling'the admission of steam to said port; a shaft having a cam'secured thereon operating as theadmission cam and as the full-gear cut-off cam; another shaft having a cut-off cam secured thereon, said cut-off cam having a cam face sufficiently longer than the cam face of said first mentioned cam so that said cut-off cam operates fto as the cut-off cam for all but full-gear cut-off;

' means for rotating said shafts in unison operably dependent upon the rotation of said driving wheels; means for rotating said cut-off cam shaft independently of the rotation of said first men-n tioned cam shaft to adjust the phase of said outoff cam relative to said first mentioned cam to vary the point of cut-off of steam; and means connecting said valve with said cams for joint operation thereby including an element operab1y=:.- engaging said first mentioned cam and another element operably engaging said cut-off cam.

6. In a steam locomotive, the combination of driving wheels; a steam power cylinder having a port; a piston for said cylinders; avalve control- '65 ling the admission of steam to said port; a shaft having a cam secured thereon operating as the admission cam and as the full-gear cut-ofi cam;

another shaft having a cut-off cam secured thereon operating as the cut-off cam for all but fullgear cut-off, said cut-off cam having a longer cam face than said first mentioned cam; means for rotating said shafts in unison operably dependent upon the rotation of said driving wheels; means for rotating said cut-off cam shaft independently of the rotation of said first mentioned cam shaft to adjust the phase of said cut-off cam relative to said first mentioned cam to vary the point of cutoff of steam; means for rotating said first mentioned cam shaft independently of the rotation of said cut-off cam shaft to adjust the phase of said first mentioned cam relative to said cut-off cam to vary the point of steam admission; and means connecting said valve with said cams for joint operation thereby including an element operably engaging said first mentioned cam and another element operably engaging said cut-01f cam.

7. In a steam locomotive, the combination of driving wheels; a steam power cylinder having a port; a piston for said cylinder; a valve controlling the admission of steam to said port; a shaft having a cam secured thereon operating as the admission cam; another shaft having a cut-off cam secured thereon; separate worm drive means for rotating said shafts, each including a worm wheel operably dependent for rotation upon the rotation of said driving wheels, a worm wheel on its correlated cam shaft, reversely pitched worms coacting one with each of said Worm wheels, and a shaft connecting said worms, said admission cam shaft drive further including a power fluid cylinder at its forward end portion for moving its worms and connecting shaft axially as a unit rearwardly to reverse the locomotive, a power fluid cylinder at its rearward end for moving its said worms and connecting shaft axially as a unit forwardly to restore said locomotive to forward motion, and a power fluid cylinder forwardly of said forward end portion power fluid cylinder for moving its said worms and connecting shaft axially as a unit rear wardly a short distance to provide preadniission of steam; and means connecting said valve with said cams for joint operation thereby including an element operably engaging said admission cam and another element operably engaging said outoff cam.

ROGER W. CLIFFORD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS (Addition to No. 413,752) 

